package com.linwen.excise.niuke._20;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * @author wlw
 * @date 2023/3/2 10:40 PM
 */
public class _10字符个数统计 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        char[] chars = str.toCharArray();
        Set<Character> set = new HashSet();
        for (char aChar : chars) {
            set.add(aChar);
        }
        System.out.println(set.size());
    }
}
